Hydrophobic
tributyltin (TBT) compounds at concentrations greater than 10 microM caused
hemolysis of human erythrocytes and formed structures in plasma membranes. The
mercapto compounds, beta-
mercaptoethanol (beta MER),
2,3-dimercaptopropanol (BAL), 2,3-dimercapto-1-propane sulfonate (
DMPS), DL-
dithiothreitol (DTT), and meso-2,3-dimercaptosuccinic
acid (
DMSA) were examined for their ability to inhibit TBT mediated
hemolysis. The relative order of effectiveness for inhibition of TBT mediated
hemolysis was BAL greater than DTT greater than
DMSA greater than
DMPS greater than beta MER. A four-fold excess of BAL over TBT prevented
hemolysis for 4 hrs and addition of BAL 0.5 hr after TBT reduced the rate of
hemolysis. The number of membrane associated TBT aggregates observed per cell profile decreased as the BAL concentration increased from 0 to 100 microM. However, the mean diameter of TBT aggregates nearly doubled in erythrocyte
suspensions at 100 microM BAL. Reactions of dimercapto compounds with lipophilic TBT aggregates may depend on their relative
lipid solubilities. Also, conversion of the weak
Lewis acid, TBT, from a four to a five or six-coordinate
tin adduct by the dimercapto
Lewis bases used could also be
a factor slowing
hemolysis rates.